138661028 has 12 divisors (see below), whose sum is σ = 264716592. Its totient is φ = 63027720.

The previous prime is 138661007. The next prime is 138661051. The reversal of 138661028 is 820166831.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1575650 + ... + 1575737.

It is an arithmetic number, because the mean of its divisors is an integer number (22059716).

Almost surely, 2^138661028 is an apocalyptic number.

It is an amenable number.

138661028 is a deficient number, since it is larger than the sum of its proper divisors (126055564).

138661028 is a wasteful number, since it uses less digits than its factorization.

138661028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3151402 (or 3151400 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 138661028 is about 11775.4417326910. The cubic root of 138661028 is about 517.5887226039.

It can be divided in two parts, 138 and 661028, that added together give a palindrome (661166).

The spelling of 138661028 in words is "one hundred thirty-eight million, six hundred sixty-one thousand, twenty-eight".